Go to the Mouse applet of the Control Panel. That's where all the mouse controls are. It's not clear what you mean by "reverse scrolling", but the mouse applet has a number of controls you can change. If your current mouse doesn't have what you want, you can always buy fancier ones that come with their own more sophisticated controls.
I bought the new HP DV6 laptop with windows 8 and I am facing little problems
how can I reverse the mouse scrolling with 2 fingers? because I use Mac and I got used to scroll in the inverse way of this HP